How can I (easily) create particles falling from the ground
Make particles fall off from the engine is a rather easy task.

you need to define some faces as the emitter, for example, the rocket engine. Assign the faces to a Vertex Group. Alternatively create a simple object (circle) that is used as an emitter, place it in front of the rocket engine, and parent it to the rocket. The extra object can be excluded from render (Particle Properties &gt; Render &gt; [_] Show Emitter).
add an Ico Sphere (very low-poly, just 1 subdivision in create popup dialog), scale it down to 1 cm. This is your particle object. Give it a material with an Emission to make it glow. Enable Bloom in Eevee
add the Particle System to the rocket and adjust a few settings:

type is Emitter, increase the Number of particles to something like 5000, and set Lifetime to 20 (or higher for a longer tail), Frame Start to 1, End to 200
set Velocity &gt; Normal to 10 m/s to speed up the particles, and Velocity &gt; Object Velocity to something like 0.482. This makes the tail a little &quot;fringy&quot;
in the section Physics &gt; Forces give the particles some Damp, like 0.121, so they don't bounce around like crazy.
in Render set Render As to Object, set Scale to 1.0 (adjust if needed), and select the particle object (Ico Sphere) as Render &gt; Object &gt; Instance Object
if you have defined a vertex group for the emitting faces you can specify it under Vertex Groups &gt; Density.




Have a good rocket launch!